In answer to your question, probably yes.
Check this information out before progressing, then check the cost ratio given by each party offering the service. below is a short description of the 2 services
ADSL
The problem with some companies that claim ADSL is the be all and end all of connection options is they are giving you the maximum figures, not the expected figures.
The first question to ask is what is the Contention ratio they are operating. This is the ammount of users connected on the ADSL circuit you are using. The higher the contention ration the slower the connection you experience.
Then you have to weigh up the price against the cost of a standard phone line. As ADSL is always on, so you only pay the monthly connection charge + phone line rental (UK Only other countries may differ).
For a complete explanation in English on ADSL FAQ goto this address paying particular attention to the information about Contention Ratios.
http://www.pipex.net/adsl/faq.shtml#content
SDSL
At this web address you can find info out about SDSL,
http://www.orckit.com/fr_dsl_faq.html
which according to your supplier could offer you a speed of 192k each way. This would mean he is offering you a contention ratio of 4 to 1.
Pros and Cons
In some cases a guaranteed speed of 192k is faster than a risk of 384k between 20 + users. Check the price and if it is good for SDSL and the contract is not to binding then my recommendation would be the SDSL. At least you can guarantee a speed every time.